Step 1: Mix graham cracker crumbs and melted butter in a bowl until the mixture resembles wet sand. Press firmly into the bottom of a 9-inch springform pan and chill in the freezer for 15 minutes.
Step 2: In a large bowl, beat the softened cream cheese and sugar until smooth and airy. Stir in the vanilla extract.
Step 3: Dissolve 1 tbsp of unflavored gelatin in 1/4 cup of warm water, then slowly fold it into the cream cheese mixture along with the whipped heavy cream until fully incorporated.
Step 4: Pour the cheesecake filling over the chilled crust and smooth the top with a spatula. Refrigerate for at least 4 hours or until the surface is firm to the touch.
Step 5: Prepare the jelly layer by dissolving the strawberry jelly powder in 1 cup of boiling water. Stir in 1/2 cup of cold water and let it cool to room temperature (do not let it set).
Step 6: Arrange the fresh strawberry slices over the set cheesecake layer. Carefully pour the cooled jelly mixture over the strawberries.
Step 7: Refrigerate the entire strawberry jelly cheesecake recipe for at least 4 more hours, or preferably overnight, before releasing from the springform pan and serving.